GII/GIII transmission system

Abstract

A document is moved across a scanner unit and successive PEL lines are scanned. Reflected light from the document with the high PEL density produces binary signal 1 or 0 in accordance with the amount of the reflected light received by the scanner. The PEL data of binary 1 or 0 of one PEL line are serially supplied to a serial parallel conversion circuit, which converts the input serial data to a parallel data and supplies the parallel data to a two PEL line buffer. The two PEL line buffer stores PEL data of the succeeding two PEL lines. Sample windows are set up and the size of the sample windows is selected as equal to the PEL size. The sample windows enclose four bits which are used to access a conversion table. The four bits in the sample window produce sixteen combinations of the white or black PELs. The conversion table stores sixteen data or entries which represent degree of amplitude modulation for the carrier signal of the transmission mode. A modulator within the system modulates the amplitude of the carrier signal of the transmission mode using AM-PM-VSB, in accordance with the bit combination sampled by the sample window, such as by the distribution status or the position of black or white high density PELs enclosed by the sample window.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patents is: 
     
       1. A method for transmitting data representing PELs of an image each of said PELs having a given size, in which said size of said PEL is smaller than the size of a PEL in digital GII transmission mode through GII transmission system using AM-PM-VSB wherein said GII transmission system includes a carrier signal having a given amplitude, comprising the steps of; scanning said image for producing PEL data representing white or black levels of said small size PELs of said image;   sampling said PEL data by a sample window which is equal to said size of PEL in digital GII transmission mode, said white or black PEL data occupying a specific position in said sample window;   detecting said position of said white or black PEL data in said sample window; and   modulating said amplitude of said carrier signal of said GII transmission system in response to said detected position.   
     
     
       2. A method according to claim 1 wherein said step of scanning further includes the steps of reflecting light off said image wherein said light reflected off said image varies in amount corresponding to said scanned image and generating 1 or 0 binary image PEL data signals in accordance with said amount of said reflected light. 
     
     
       3. A method according to claim 2 wherein said step of sampling further includes the step of sampling a plurality of said 1 or 0 binary image PEL data signals representative of one PEL in said GII transmission mode. 
     
     
       4. A method according to claim 3 wherein said step of detecting includes the step of producing an amplitude signal representative of the 1 or 0 binary signals in each plurality of said 1 or 0 binary image PEL data signals. 
     
     
       5. A method according to claim 4 wherein said step of modulating includes the step of modulating the amplitude of said carrier signal of said GII transmission system in accordance with said amplitudes produced by said step of detecting. 
     
     
       6. In a GII digital transmission system for transmitting data representing PELs of an image appearing on a document or the like, in which said size of each of said PELs of said image is smaller than the size of a PEL in digital GII transmission mode through GII transmission system using AM-PM-VSB, data modifying structure comprising: means for scanning said image for producing PEL data representing white or black levels of said small size PELs of said image;   sampling means connected to said scanning means for sampling said PEL data by a sample window which is equal to said size of PEL in digital GII transmission mode;   detecting means connected to said sampling means for detecting positions of white or black PEL data in said sample window; and   modulating means connected to said detecting means for modulating said amplitude of said carrier signal of said GII transmission system in response to said detected position.   
     
     
       7. Data modifying structure in a system according to claim 6 wherein said scanning means includes means for reflecting light on said image and producing binary 1 or 0 signal in accordance with said amount of said reflected light, and buffer storage means for storing said binary 1 or 0 signals. 
     
     
       8. Data modifying structure in a system according to claim 7 wherein said sampling means includes means for addressing said buffer storage means for sampling groups of signals from said buffer storage means, each of said groups consisting of the stored 1 and 0 signals for a plurality of said smaller size image PELs at one time. 
     
     
       9. Data modifying structure in a system according to claim 8 wherein said detecting means includes means for producing a plurality of signals, each of said plurality signals having an amplitude representative of the 1 bit signals and 0 bit signals in each one of said groups of said plurality of smaller size image PELs stored in said buffer storage means. 
     
     
       10. Data modifying structure in a system according to claim 9 wherein said modulating means includes means for modulating the amplitude of the said carrier signal of said GII transmission system in accordance with said amplitudes of said plurality of signals from said detecting means representative of said groups of 1 and 0 binary signals.